Wearables are widely used for mobile health monitoring, and photoplethysmography (PPG) is a key sensing modality for heart rate and related physiological measurements. However, public in-the-wild PPG datasets remain largely wrist-centric or limited to short, controlled studies, constraining research on emerging wearable form factors. We present Multi-site PPG, an in-the-wild physiological dataset collected from four custom-developed unobtrusive wearables: a smart earring, ring, watch, and necklace. Each device records green and infrared reflective PPG, 3-axis acceleration, and temperature with timestamps for cross-device alignment, while a Polar H10 chest strap provides reference electrocardiogram (ECG). Participants wore the devices for multiple days during daytime activities while continuing their normal routines. The dataset contains over 350 hours of raw data and 230-290 hours of modeling-ready 8-second windows per wearable. We benchmark heuristic, supervised, and self-supervised heart-rate estimation methods, showing substantial body-site differences: the best methods achieve mean absolute errors (MAEs) of 2.30 bpm on the earring, 5.13 bpm on the ring, 8.37 bpm on the watch, and 8.68 bpm on the necklace. We further analyze motion effects and evaluate multi-site and PPG-accelerometer fusion, demonstrating the dataset's value for robust physiological sensing across emerging wearable form factors.

翻译：可穿戴设备广泛应用于移动健康监测，光电容积描记（PPG）是心率及相关生理测量的关键感知模态。然而，现有的野外环境PPG公开数据集仍以手腕为中心，或局限于短期控制性研究，限制了新兴可穿戴形态的研究。我们提出多点位PPG（Multi-site PPG）——一个从四款定制开发的低干扰可穿戴设备采集的野外生理数据集：智能耳环、戒指、手表和项链。每个设备记录绿色和红外反射式PPG、三轴加速度及体温数据，并附时间戳以实现跨设备同步，同时以Polar H10胸带提供参考心电图（ECG）。参与者在日间活动期间佩戴设备多天，维持正常作息。该数据集包含超过350小时的原始数据，每款可穿戴设备提供230-290小时的建模就绪8秒窗口。我们对比了启发式、监督式和自监督式心率估计方法，揭示了显著的身体部位差异：最佳方法在耳环、戒指、手表和项链上的平均绝对误差（MAE）分别为2.30 bpm、5.13 bpm、8.37 bpm和8.68 bpm。我们进一步分析了运动影响，并评估了多点位与PPG-加速度计融合，证明了该数据集对新兴可穿戴形态鲁棒生理感知的价值。